Question on Swapping

[Doug Hardie]

I have a question about what I am seeing on several servers.  These are 4 core machines with more than the needed memory.  Load is never above .5 and memory usually shows over half free.  I have never seen it even close to the limit (including buffers).  Basically these are lightly used servers.  However, top often shows after a few weeks of uptime that some of the unused gettys are swapped out.  I didn't really expect this as lack of memory is not an issue.  Is there something in FreeBSD 7 and 8 that causes a process thats idle for very log times to get swapped out?  I haven't seen anything like that in the various documentation files, but it sure looks like thats the case.